Means on discrete product lattices

We investigate the problem of averaging values on lattices, and in particular on discrete product lattices. This problem arises in image processing when several color values given in RGB, HSL, or another coding scheme, need to be combined. We show how the arithmetic mean and the median can be constructed by minimizing appropriate penalties. We also discuss which of them coincide with the Cartesian product of the standard mean and median.

The median and its extensions

We review various representations of the median and related aggregation functions. An advantage of the median is that it discards extreme values of the inputs, and hence exhibits a better central tendency than the arithmetic mean. However, the value of the median depends on only one or two central inputs. Our aim is to design median-like aggregation functions whose value depends on several central inputs. Such functions will preserve the stability of the median against extreme values, but will take more inputs into account. A method based on graduation curves is presented.

Image reduction using means on discrete product lattices

We investigate the problem of averaging values on lattices, and in particular on discrete product lattices. This problem arises in image processing when several color values given in RGB, HSL, or another coding scheme, need to be combined. We show how the arithmetic mean and the median can be constructed by minimizing appropriate penalties, and we discuss which of them coincide with the Cartesian product of the standard mean and median. We apply these functions in image processing. We present three algorithms for color image reduction based on minimizing penalty functions on discrete product lattices.

On extending generalized Bonferroni means to Atanassov orthopairs in decision making contexts

Extensions of aggregation functions to Atanassov orthopairs (often referred to as intuitionistic fuzzy sets or AIFS) usually involve replacing the standard arithmetic operations with those defined for the membership and non-membership orthopairs. One problem with such constructions is that the usual choice of operations has led to formulas which do not generalize the aggregation of ordinary fuzzy sets (where the membership and non-membership values add to 1). Previous extensions of the weighted arithmetic mean and ordered weighted averaging operator also have the absorbent element 〈1,0〉, which becomes particularly problematic in the case of the Bonferroni mean, whose generalizations are useful for modeling mandatory requirements. As well as considering the consistency and interpretability of the operations used for their construction, we hold that it is also important for aggregation functions over higher order fuzzy sets to exhibit analogous behavior to their standard definitions. After highlighting the main drawbacks of existing Bonferroni means defined for Atanassov orthopairs and interval data, we present two alternative methods for extending the generalized Bonferroni mean. Both lead to functions with properties more consistent with the original Bonferroni mean, and which coincide in the case of ordinary fuzzy values.

Aggregation of preferences in recommender systems

This chapter gives an overview of aggregation functions toward their use in recommender systems. Simple aggregation functions such as the arithmetic mean are often employed to aggregate user features, item ratings, measures of similarity, etc., however many other aggregation functions exist which could deliver increased accuracy and flexibility to many systems. We provide definitions of some important families and properties, sophisticated methods of construction, and various examples of aggregation functions in the domain of recommender systems.

Color image reduction by minimizing penalty functions

In image processing, particularly in image reduction, averaging aggregation functions play an important role. In this work we study the aggregation of color values (RGB) and we present an image reduction algorithm for RGB color images. For this purpose, we define and study aggregation functions and penalty functions in product lattices. We show how the arithmetic mean and the median can be obtained by minimizing specific penalty functions. Moreover, we study other penalty functions and we show that, in general, aggregation functions on product lattices do not coincide with the cartesian product of the corresponding aggregation functions. Finally, we make an experimental study where we test our reduction algorithm and we analyze the stability of the penalty functions in images affected by noise.

On some properties of weighted averaging with variable weights

Density-based means have been recently proposed as a method for dealing with outliers in the stream processing of data. Derived from a weighted arithmetic mean with variable weights that depend on the location of all data samples, these functions are not monotonic and hence cannot be classified as aggregation functions. In this article we establish the weak monotonicity of this class of averaging functions and use this to establish robust generalisations of these means. Specifically, we find that as proposed, the density based means are only robust to isolated outliers. However, by using penalty based formalisms of averaging functions and applying more sophisticated and robust density estimators, we are able to define a broader family of density based means that are more effective at filtering both isolated and clustered outliers. © 2014 Elsevier Inc. All rights reserved.

A penalty-based aggregation operator for non-convex intervals

In the case of real-valued inputs, averaging aggregation functions have been studied extensively with results arising in fields including probability and statistics, fuzzy decision-making, and various sciences. Although much of the behavior of aggregation functions when combining standard fuzzy membership values is well established, extensions to interval-valued fuzzy sets, hesitant fuzzy sets, and other new domains pose a number of difficulties. The aggregation of non-convex or discontinuous intervals is usually approached in line with the extension principle, i.e. by aggregating all real-valued input vectors lying within the interval boundaries and taking the union as the final output. Although this is consistent with the aggregation of convex interval inputs, in the non-convex case such operators are not idempotent and may result in outputs which do not faithfully summarize or represent the set of inputs. After giving an overview of the treatment of non-convex intervals and their associated interpretations, we propose a novel extension of the arithmetic mean based on penalty functions that provides a representative output and satisfies idempotency.

Avaliação da reprodutibilidade dos parâmetros de adequação da hemodiálise crônica

Justificativa: Doses inadequadas de diálise estão associadas a maior morbidade e mortalidade em pacientes com uremia terminal em tratamento hemodialítico. Atualmente os métodos mais utilizados para medir a adequação da hemodiálise baseiam-se no cálculo da depuração fracional de uréia (Kt/V) e da taxa de redução da uréia (URR). Nesse estudo avaliou-se a reprodutibilidade do Kt/V e da URR e analisou-se o número aceitável de medidas mensais destes parâmetros para determinar de forma fidedigna a adequação da hemodiálise. Métodos: Avaliamos 43 pacientes clinicamente estáveis, em cinco sessões de hemodiálise (sessões 1 a 5), durante três semanas. Três diálises consecutivas na primeira semana (sessões 1, 2, 3) e duas sessões de meio de semana, nas duas semanas subseqüentes (sessões 4 e 5). Resultados: Não houve diferença entre a média dos Kt/Vs obtidos em diálises seqüenciais (1, 2 e 3) comparada a média dos Kt/Vs obtidos em diálises no meio da semana (2, 4 e 5). O mesmo aconteceu com a URR e com os coeficientes de variação do Kt/V e da URR. Também não encontramos diferença entre uma medida mensal (Kt/V 2) e três medidas mensais (média dos Kt/Vs 2, 4 e 5). O mesmo ocorreu com a URR. A diferença entre o Kt/V 2 e a média dos Kt/Vs 2, 4 e 5 foi de – 0,02 unidades e entre a URR 2 em relação a média das URRs 2, 4 e 5 foi de – 0,5%. Além disso, se fizermos apenas uma medida mensal (Kt/V 2) 80% dos pacientes estarão a uma distância de no máximo 0,16 unidades abaixo da média dos Kt/Vs 2, 4 e 5 e no máximo 0,12 unidades acima. Em relação a URR 80% dos pacientes estarão a uma distância de no máximo 4,37% abaixo da média das URRs 2, 4 e 5 e no máximo 3,37% acima. O grau de concordância entre o Kt/V 2 e a média dos Kt/Vs 2, 4 e 5 é bom para pontos de corte do Kt/V igual ou superior a 1,3. No caso da URR a concordância é boa para pontos de corte acima de 65%. Conclusão: Concluímos que nesta população de pacientes clinicamente estáveis os parâmetros de adequação da hemodiálise mostraram-se reprodutíveis não havendo necessidade de aumentar o número de medidas mensais da quantidade de diálise ofertada.

Cultura organizacional e comprometimento dos funcionários do Soleil Suíte Hotel

This study examines the relationship of the types of organizational culture perceived in a business hotel with the nature of the link between individual and organization. This linkage between commitment and organizational culture has been little explored, both national and international, requiring more studies. Thus, the survey was conducted in Soleil Suite Hotel, located on the beach of Ponta Negra, city of Natal, Rio Grande do Norte. The independent variable of the proposed model was represented by the types of organizational culture, while the dependent variable was represented by the four dimensions of commitment. It was used in addition to the correspondence analysis, the arithmetic mean, the Pearson s correlation and the simple regression analysis. The results indicated the existence of relationship of the types of organizational culture with the kind of commitment shown by the officials, where the cultures of Group and Innovative, capable of generating an environment dedicated to the work as a team, the development and professional growth of the employees, as well as the creativity and individual freedom of each one to try new things, encourage the dominance of the dimensions Affective, Affiliative and Normative of the tie person-organization

Dois critérios de seleção na pré- desmama em bovinos da raça Gir. 2. Efeito na classificação dos animais

A utilização de dois critérios de seleção na pré-desmama, ganho médio diário do nascimento à desmama (GMD) e dias para ganhar 160 kg do nascimento à desmama (D160), foi estudada, analisando-se informações de 16.592 animais, provenientes do controle de desenvolvimento ponderal da Associação Brasileira dos Criadores de Zebu, nascidos no período de 1978 a 1994. Foram incluídos no modelo o efeito fixo de grupo de contemporâneos e os efeitos aleatórios genético aditivo de animal e materno, de ambiente permanente materno e o erro. A covariância entre os efeitos direto e materno foi considerada igual a zero. As estimativas dos componentes de variância e herdabilidade foram obtidas pelo método da máxima verossimilhança restrita e os valores genéticos preditos (VGs), por modelos animais uni-característica. As estimativas de herdabilidade foram: 0,12; 0,05; 0,10 e 0,05 para GMD (efeito direto), GMD (efeito materno), D160 (efeito direto) e D160 (efeito materno), respectivamente. Foram estimadas a correlação genética entre GMD e D160 (efeito direto e materno) e a correlação de classificação (Spearman) entre os valores genéticos para as categorias de touros, vacas e bezerros. As estimativas de correlação genética entre GMD e D160 foram 0,86 e 0,88, para o efeito direto e materno, respectivamente. As estimativas de correlação de ;rank;, também foram altas, entretanto, nenhuma foi igual a um, resultando em alterações na classificação dos animais. A relação entre as médias aritmética (A) e harmônica (H) e o desvio-padrão (S) do GMD ajustado para efeitos ambientais e maternos (GMDc) foi verificada utilizando-se um modelo restrito, sem intercepto, mediante as regressões linear e quadrática do S do GMDc sobre a diferença entre a média aritmética e média harmônica (A-H). Os resultados evidenciaram que, semelhantemente a H, o critério D160 apresentou a propriedade de discriminar touros com progênie mais uniforme.

Multiple resistance to anthelmintics by Haemonchus contortus and Trichostrongylus colubriformis in sheep in Brazil

The objective of this study was to determine the level of resistance of Haemonchus contortus and Trichostrongylus colubriformis in sheep to levamisole albendazole ivermectin moxidectin closantel and trichlorfon The parasites were isolated from sheep naturally infected by gastrointestinal nematodes and were then kept in monospecifically infected lambs for production of infective larvae (L3) of both species Forty-two lambs at three months of age were simultaneously artificially infected with 4000 L3 of H contortus and 4000 L3 of T colubriformis The animals were allocated Into seven groups with six animals each that received one of the following treatments Group 1-control no treatment Group 2-moxidectin (0 2 mg/kg body weight (BW)) Group 3-closantel (10 mg/kg BW) Group 4-trichlorfon (100 mg/kg BW) Group 5-levamisole phosphate (4 7 mg/kg BW) Group 6-albendazole (5 0 mg/kg BW) and Group 7-ivermectin (0 2 mg/kg BW) Nematode fecal egg counts (FEC) were carried out on the day of treatment and again at 3 7 10 and 14 days post-treatment on the same occasions composite fecal cultures were prepared for each group for production of L3 which were identified into genus The animals were sacrificed for worm counts at 14 days after treatment The efficacy of each treatment was calculated from the arithmetic mean of the FEC or worm burden of the treated group compared with the values of the control group Only trichlorfon and moxidectin treatments resulted in a significant reduction of H contortus recorded at necropsy (73% and 45% respectively) Moxidectin reduced T colubriformis worm burdens by 82% and albendazole by 19% All other anthelmintics resulted in no significant reduction in the numbers of worms found at necropsy In conclusion the Isolates of H contortus and T colubriformis showed multiple resistance to all groups of anthelmintics tested This is the first report based on the controlled efficacy test to show resistance of T colubriformis to macrocyclic lactones in Brazil (C) 2010 Elsevier B.V. All rights reserved

A model for the plankton system of the Broa reservoir, Sao Carlos, Brazil

In this paper a model, called ELLOBO running in STELLA II, was set to describe the plankton system of the Broa reservoir (SP). The three state variables of the model are: phytoplankton, zooplankton, and the fish Astyanax fasciatus. The forcing variables are: temperature, nitrate, phosphorus and solar radiation. The model did not consider the cycling of nutrients inside the reservoir. The results show that: temperature is the principal forcing variable in the phytoplankton dynamic and in the subsequent evolution of the whole system. The zooplankton predation was described by Odum's equation, and there is a strong random component in zooplankton grazing, which was essential for the model, because zooplankton estimates have high variance. One must collect data in a short space of time (maybe daily) to better explain the zooplankton and phytoplankton variation. Validation was performed using simple statistics (arithmetic mean, standard deviation) and the results show concordance between observed and simulated values. Overhead was used to calibrate some parameters and to validate the model. The highest overhead value (5%) imply in the better accordance between estimated and;observed state variables values. We believe this approach in Broa reservoir will provide an useful tool for future research and it could be used comparatively in other continental aquatic ecosystems. (C) 2000 Elsevier B.V. B.V. All rights reserved.

Genetic diversity of Stryphnodendron adstringens (Mart.) Coville determined by AFLP molecular markers

Bark extracts of Stryphnodendron adstringens (Mart) Coville a Leguminosae species, well known in Brazil as barbatimao, are popularly used as healing agent. The objective of this work was to determine the genetic diversity of S. adstringens populations and to correlate genetic distances to the production of tannins. S. adstringens accessions from populations found in Cerrado regions in the states of Goias, Minas Gerais and São Paulo were analyzed using the AFLP (Amplified Fragment Length Polymorphism) technique. A total of 236 polymorphic bands were scored and higher proportion of genetic diversity was found inter populations (70.9%), rather than intra populations (29.1%). F-ST value was found to be significantly greater than zero (0.2906), demonstrating the complex genetic structure of S. adstringens populations. Accessions collected in Cristalina, GO, showed higher percentage of polymorphic loci (87.3%) and the highest genetic diversity. The lowest genetic variability was detected among accessions from the population growing in Caldas Novas, GO. The genetic distance among populations was estimated using the Unweighted Pair Group Method with Arithmetic Mean (UPGMA), which grouped populations into 3 clusters. Moreover, chemotypes with tannin concentration above 40% showed higher genetic similarity. AFLP analysis proved to be an efficient gene mapping technique to determine the genetic diversity among remaining populations of S. adstringens. Obtained results may be employed to implement further strategies for the conservation of this medicinal plant. (C) 2011 Elsevier Ltd. All rights reserved.

Genetic data of 15 autosomal STR loci: an analysis of the Araraquara population colonization (São Paulo, Brazil)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)